1. Field of the Invention
This invention relates broadly to tube couplings. More particularly, this invention relates to end fitting tube couplings which can quickly and securely connect a tube to a port without the need for additional retaining means.
2. State of the Art
Hot tubs, spas, and bathtubs are generally relatively deep tubs formed by rotational molding, blow-molding or vacuum-forming. The tubs are provided with a number of fixtures including water jet assemblies. The appeal of hot tubs and spas is primarily due to the hydrotherapy provided by pressurized water jet assemblies recessed into the tub wall which provide a massaging action.
In particular, each hydrotherapy jet assembly is connected via flexible conduits to water and air manifolds which supply pressurized water and air to each jet assembly of the spa tub. The pressurized water flows through a hydrotherapy jet assembly having an expanded throat, i.e., a venturi. As the water flows through the expanded throat, the water at the center of the throat moves more rapidly than the water along the sides of the nozzle. As a result, a low pressure area is created at the center of the throat. Air is drawn from an inlet into the low pressure area and mixes with the water. The mixture of pressurized water and air thereby provide an aerated therapeutic jet of water.
Hydrotherapy jet fixtures are generally installed in a hole in the tub wall, with the fixture outlet directed into the interior of the tub. The rear of the fixture includes an air inlet and a water inlet connected to plumbing which separately provides air and water supplies. The connections of the jet fixture to the plumbing is typically a serpentine collection of flexible conduits which each must be coupled between a manifold and the respective jet fixtures at the time of spa plumbing installation. The current method of installation is undesirable for several reasons. First, all connections between plumbing fixtures (air manifold, water manifold, and spa jet fixtures) are made at the time of installation. This requires a large number of connections to be made at the installation site in typically cramped working conditions. Moreover, it may be difficult to reach and accomplish the connection due to the location of a particular jet fixture. Second, each plumbing connection (at the manifold side and water and air inlets) must be glued or clamped in position by a skilled worker. If the connection is glued, several steps must be performed: opening the glue container, using an applicator to remove glue from the container, applying the glue to the outside of an end of a conduit, closing the glue container, inserting the end of the conduit into a respective slip fitting in a plumbing fixture, and holding the conduit relative to the plumbing fixture until the glue sets to secure the connection. This process must be repeated for each glued connection and can be time consuming and exhausting, particularly at hard-to-reach connections. Also, gluing requires good ventilation and a respirator should be used to avoid inhaling the glue fumes. If the connection is clamped, special tools are required and it may be difficult to utilize the tools for tightening the clamp about the conduit in the space available. Furthermore, in cramped location it is difficult to properly center the clamp over the conduit such that even pressure is provided about the conduit. When clamping is uneven, leaking may result or the connection may even completely disconnect over time.
It is therefore an object of the invention to provide a tube coupling system which is easy to use, has a minimum number of parts, and forms a strong, secure, and water-tight seal between a flexible tube and a port element
It is another object of the invention to provide a tube coupling system which requires little technician training, and which can secure a tubing to a port element without the need for tools or additional retaining means.
It is a further object of the invention to provide a tube coupling system which is self-centering to prevent coupling failures.
It is an additional object of the invention to provide a tube coupling system which is particularly suitable for spa tub fixtures and plumbing.
It is also an object of the invention to provide a tube coupling system which permits partial assembly prior to arriving at a job site thereby facilitating quick installations.
It is yet another object of the invention to provide a tube coupling system which is inexpensive to manufacture, reliable, and simple to install.
In accord with these objects, which will be discussed in detail below, a coupling system for coupling flexible tubing between ports, e.g., between a manifold and a spa jet assembly in spa tub plumbing is provided. The coupling system includes a component having a port element over which the tubing is provided, and a clamp which is lockable to the port element and maintains the tubing on the port element in a fluid-tight seal. The port element includes a barb and catch preferably defined by a beveled or tapered lip and a preferably circumferential groove defined behind the lip. The clamp is substantially cylindrical and generally has first and second ends and an axial channel therethrough. The first end of the clamp is formed as a plurality of generally axially extending resilient, yet stiff, fingers separated by gaps and spaced equidistantly apart around the circumference of the first end of the clamp. The fingers have a tip and an inner surface having a barbed portion near the tip. The fingers are biased slightly inward toward a center of the channel to define an inner diameter which is smaller than the outer diameter of the tubing. A diameter at the second end of the clamp is preferably larger than a diameter of the tubing to allow for easier installation of the tubing through the channel of the clamp. A diameter of a central clamping portion of the channel between the first end and the second end is slightly larger than the diameter of the barb of the port element, such that when tubing is positioned over the barb, the clamp snugly grips the tubing between the clamping potion and the barb.
In use, the tubing is inserted through the second end of the clamp, and the tubing is then positioned over the barb of the port element. The clamp is then forcibly slid along the tubing such that the barbed flanges ride over the port element and the lip until the flanges lock in the groove. This simple and quick operation creates a self-aligning water-tight seal between the port element and the tubing. No additional sealing means or clamp retention means are required.
According to another preferred aspect of the invention, the second end of the clamp is provided with a plurality of alternating pegs and holes oriented parallel to the axis of the clamp. The alternating pegs and holes on the second end of a first clamp correspond to alternating holes and pegs on the second end of a second clamp such that the second ends of two clamps can be detachably coupled in an interference fit between the respective pegs and holes. As such, the pair of clamps may be provided onto tubing, with one of the clamps optionally securing a first end of the tubing to a port portion of a component. This partial assembly may be performed off-site and the connection at the second end of the tubing may be completed at a job site. That is, once at the job site, the second end of the tubing is provided over the barb of a second port portion of a second component, the second clamp is decoupled from the first clamp and slid along the tubing to the second port portion, and second clamp is moved to secure the tubing the second port portion as described above.
Additional objects and advantages of the invention will become apparent to those skilled in the art upon reference to the detailed description taken in conjunction with the provided figures.